(1144) Risk Factors and Clinical Outcomes of Ventilator-Associated Tracheobronchitis

Introduction: Despite advancements in critical care and mechanical ventilation practices, ventilator-associated tracheobronchitis (VAT) remains a prevalent issue in intensive care units (ICUs). We aimed to identify risk factors for the development and severe course of VAT in patients on prolonged mechanical ventilation (PMV).

Methods: This retrospective cohort study evaluated the VAT incidence from 2018 to 2022 in 724 patients on PMV for more than 48 hours. VAT diagnosis was based on clinical signs (fever ≥38°C, leukocytosis ≥12,000 cells/ml, or leukopenia ≤4,000 cells/ml, purulent endotracheal secretions, or conversion to purulent), radiological findings (no progression of existing or emergence of new pulmonary infiltrates), and microbiological criteria.

Results: The VAT incidence rate significantly decreased from 24.7% to 10.1% (p=0.003) over the study period. The incidence of the most severe VAT (hemorrhagic catarrhal purulent) also decreased from 44.7% to 14.3% (p=0.034). The duration of PMV and ICU stay in patients with VAT decreased from 202.1±6.15 hours to 125.3±7.81 hours (p=0.0001), and from 9.7±0.25 days to 6.6±0.3 days (p=0.0001), respectively. Patients with VAT (n=122) had a higher incidence of concomitant COPD compared to those without VAT (n=602) — 22.9% vs 10.6%, respectively (p=0.001). Gram-negative bacteria were the leading cause of severe tracheobronchitis, including Acinetobacter spp. (24%), Kl. pneumoniae (11.6%), Ps. aeruginosa (13.0%), and E. coli (10.6%). Less frequently isolated pathogens included Staphylococcus aureus (5.3%), Enterococcus spp. (2.2%), and Candida fungi (17.0%). The identified predictors of severe VAT were age over 60 years (OR=2.28; 95% CI 1.0–4.9), SAPS II score over 40 (OR=5.9; 95% CI 2.6–13.8), duration of mechanical ventilation over 144 hours (OR=5.4; 95% CI 1.8–16.7), and the presence of malignant neoplasms (OR=2.83; 95% CI 1.2–6.9).

Conclusions: The significant decrease in VAT incidence rates and the reduced duration of mechanical ventilation and ICU stay indicate effective VAT prevention and treatment strategies over the study period. Identifying factors associated with VAT development and predictors of severe VAT can help in recognizing high-risk patients and improving their management.